* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    display: flex;
    align-items: stretch;
    justify-content: space-between;
}

aside {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    background-color: hsl(224, 97%, 34%);
    width: 240px;
    text-align: center;
    box-shadow: 5px 0 15px 0 #000;
}

aside h1 {
    font-size: 2rem;
    line-height: 4rem;
}

aside h1 a {
    text-decoration: none;
    color: hsl(0, 0%, 100%);
}

aside section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

aside section h2 {
    width: 100%;
    background-color: hsla(0, 0%, 100%, .3);
    line-height: 2em;
}

aside section a {
    width: 100%;
    color: hsl(0, 0%, 100%);
    text-decoration: none;
    line-height: 2.8em;
}


aside section a:hover {
    background-color: hsla(0, 0%, 100%, .3);
}

main {
    margin-left: 240px;
    width: calc(100% - 240px);
    background-image: url(../img/cat-bg.jpg);
    background-repeat: no-repeat;
    background-position: 0 0;
    background-size: cover;
    background-color: hsl(0, 0%, 83%);
    background-attachment: fixed;
}

main p.current-user {
    color: #eee;
    position: absolute;
    top: 25px;
    right: 25px;
}